Wednesday, 30 January 2013

Making a start on the O&K

With the weather still too cold and damp to start spray painting in the garage, and enthused by the Landswood Park article, I thought it a good time to start on the Nonneminstre Models O&K loco kit I got last year.

With the main parts spread out it is clear there is a fair amount of flash to clear up, and probably a bit of fettling to get the parts to fit together well. However the detail of the mouldings is as good as I have ever seen in a white metal kit. The same can't be said for that poor driver figure though...

However I should start with the chassis, which is supplied assembled without pick-ups, and for 16.5mm gauge. The instructions say to push the wheels in for 14mm gauge, easier said than done but I found placing a wheel face onto a piece of wood with a hole for the axle, and hitting the other end of the axle with a hammer, got the job done! I have a KB scale gauge which includes a back-to-back check. However the axles were then a very tight fit, so I found it necessary to file the sides of the chassis block very slightly.

There isn't space for the pick-ups to go behind the wheels at 14mm gauge so they act on the tread, so it is suggested to fit them to the underside of the chassis, though I didn't want as they may then be visible. The instructions do say "We reckon those working in 14mm gauge are wee bit able!", hmm, thanks for the confidence but I'm not so sure.

The pick-ups are made by soldering springy wire onto a piece of PCB stuck to the chassis side in such a way it won't be visible after assembly. The instructions suggest soldering one side direct to the chassis, but I didn't want to solder it to white metal. I wanted to be able to disassemble the chassis without removing pick-up wires, so a notch was cut into each side of the chassis block so the wires can route to the motor through the same hole in the footplate.

With the footplate and bottom keeper plate attached the chassis can be test run. The first attempt didn't go well, the motor couldn't seem to overcome the resistance of the chassis. So I stripped the chassis down including removing the motor and layshaft, and spent some time filing back the chassis block and adjusting the pick-ups until it could be freely rolled. The second test was much better - now running smoothly - although it needed a lot of weight to make the pick-ups work well (although the track was dirty too!). With all that gearing it will be another slow runner...

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Phil Parker said...

I might suggest slighly longer pickups - it'makes them more flexible. Insulate them from the body by smearing superglue everywhere you don't want the electric to flow.

Michael Campbell said...

Thanks Phil I'll consider that. There isn't much space though as the wheels protrude through the footplate, and the pick-ups go on top of the wheels. I think if they were much longer they'd catch on the footplate. I might see if I can get phosphor bronze strip instead of brass wire.